Liposomes are extensively used to study the interaction of proteins, peptides and other molecules with the surface of a lipid membrane. One of the parameters that affects this interaction is the charge of the liposomal membrane. Liposomes are always made in aqueous environment and they are sized to the desired size in liquid state using various methods such as high-pressure extrusion through nano sized pore track etch membranes. Liposome without water is meaningless. In rare occasions, liposomes are freeze dried and proliposomes are formed in the presence of a lyoprotectant such as trehalose. Using a lyoprotectant is necessary in order to maintain the size of the liposomes after rehydration.
Phosphatidylserine (PS) is a negatively charged molecule. The amount of the negative zeta potential in the liposomes depends on the molar percentage of the phosphatidylserine (PS) in the formulation. Anionic Lyophosome™-Phosphatidylserine (PS) catalog contains products made from 0.5 up to 90 percent DOPS with various amount of negative zeta potentials. The matrix lipid, DOPC, that is used in the formulations does not significantly contribute to the charge of the liposomes. Anionic liposomes are used in blood complement studies and various types of in vitro studies.
Lyophosome™ product catalog is composed of a large selection of freeze-dried liposomes with various types of lipids and wide range of zeta potentials and different properties. Lyophosome™ products should be used by scientists who understand liposome formulation and have the proper equipment to check the size, separate non-encapsulated drugs and do the proper assays. Freeze-dried liposomes cannot be used blindly.
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1、如果是提取的总蛋白,然后做WB,用β-actin或者GAPDH做内参肯定是没有问题的,这是公认的东西。
2、如果用膜蛋白提取试剂盒提取蛋白,再用β-actin作为内参似乎不妥,因为理论上来讲β-actin在膜上是不表达的。WB能做出β-actin来是因为膜蛋白提取时把胞质蛋白也提出来了。然而,如果我们试验目的是用药物处理细胞,比较处理前后某种膜蛋白的表达情况,此时用膜蛋白提取试剂盒提取膜蛋白后再用β-actin做内参似乎就不妥了,因为你根本不知道药物处理前后混杂了多少的胞质蛋白进来。如果没有胞质蛋白混进去的话,β-actin就是检测不到的。
转膜后就要区分与胶接触的一面与另一面了。话说楼主好奇的话可以跑蛋白的试试看哈。比如目的蛋白的胶用光滑面贴着胶,内参蛋白用粗糙面贴着胶一起转膜试试转膜结果看看呢。
考马斯亮兰染液也可以重复用。新配的染液10分钟即可,重复3次后要染30分钟。
一抗二抗可以重复利用,但是注意要在5%milk中加入0.2% sodium azide ,并且用完以后放入4度保存,我的经验重复使用4-5次是肯定没有问题的.如果保存不当,就会污染微生物,只能丢弃.
取名尿素。尿素含氮46%,是固体氮肥中含氮量最高的。尿素在酸、碱、酶作用下(酸、碱需加热)能水解生成氨和二氧化碳。希望我能帮助你解疑释惑。
之前是担心所需组织量不够(要求是200-300mg,我的组织只有20mg左右)才跑不出来,后来换用大鼠心脏测试,组织量绝对够。。。而且在跑western之前进行了说明书上的蛋白浓缩步骤,可是在加loADIngbuffer之后,蛋白沉淀怎么都溶解不掉~说明书也注明了如果有沉淀可以取上清继续上样,可是每次上样感觉样品往上浮,只有部分样品往孔里沉,而且跑出来什么都没有,连内参都没有。用的是β-actin的内参。。
western之前浓缩步骤如下:
1、取所得提取物,每100ul膜蛋白加入约300ul的溶解buffer和约100ul三氯乙酸(TCA)试剂,混匀后置冰上20-30min后,13000rpm,离心15min,尽可能去除上清。
2、沉淀加入1ml丙酮,室温静置10min后,13000rpm离心15min。
3、弃上清,沉淀真空旋干或置冰上干燥10min(敞开离心管盖),按适当体积比加入loadingbuffer(使用前没100ulloadingbuffer加入2-5ulβ-巯基乙醇)溶解,彻底分散(枪头反复吹吸或剧烈涡旋),煮沸5min。【注:加入loadingbuffer后如有部分难容物,可取上清继续上样。】
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